The present invention concerns a composition that is useful for protecting a solid substrate and its use.
It is common knowledge in protecting solid substrates against environmental attack to use biocides for this purpose. These compounds are agents that fight against or kill plants or other undesirable living organisms. The problem with the use of biocides is that they are very often water soluble and, as such, when exposed to bad weather, for example in the form of rains or floods, they will be diluted or washed out, with the result that the treated substrate is deprived of the protection of the compound. Thus, there is a need for improvements in this area so that biocide treated substrates can retain their effectiveness even under wet conditions.
The invention relates to a substrate treating composition for the protection of a solid substrate against environmental attack. This composition comprises at least one biocidal component, a hydrophobing agent, and a solvent for maintaining the component(s) and agent in a liquid phase. The biocidal component is present in an amount sufficient to retard growth or kill plants or similar living organisms while the hydrophobing agent is present in an amount effective to impart hydrophobicity to, or increase the hydrophobicity of, the substrate after the liquid composition is applied thereto.
Advantageously, the hydrophobing agent is a C1 to C4 alkyl siliconate compound or a siloxane polymer. A preferred siloxane polymer is a polydimethyl(H)siloxane.
The alkyl siliconate compound may be an alkali metal methyl siliconate present in an amount of about 0.005 to 5% by weight. Preferably, the alkyl siliconate compound is a sodium or potassium methyl siliconate and is present in an amount of about 0.1 to 2% by weight. If desired, a portion of the alkyl siliconate compound can be replaced with a silicate compound. This reduces the cost of the composition and improves performance as well.
The biocidal component of the composition is preferably a fungicide, an algicide, an insecticide, a rodenticide, a herbicide, a bactericide, or mixtures thereof. Generally, the biocidal component is present in an amount of about 100 to 10,000 ppm.
The solvent is preferably water or an alcohol/water mixture.
The invention also relates to a method of treating a substrate which comprises applying one of the solutions of the invention upon or within the substrate to retard growth or kill plants or similar living organisms on or in the substrate and to impart hydrophobicity to, or increase the hydrophobicity of, at least a portion of the substrate and to impart or to render hydrophobic a portion of the substrate after the liquid composition is applied thereto. The composition is typically applied to the substrate by topical application or by immersion.
Any of a wide variety of substrates can be treated according to the invention. Rock, stone, a stone-like material, a cement, a concrete or mixtures thereof, a wood, a textile, grains or cellulose-based products are all suitable for treatment.